Submerged pump protector



June 18, 1963 J. E. wlLDER 3,094,599

SUBMERGED PUMP PROTECTOR Filed Feb. 19. 19Go 2 sheets-sheet 1 f :l Nom/lay ausm June 18, 1963 J. E. wlLDER 3,094,599

SUBMERGED PUMP PROTECTOR Filed Feb. 19. 1960 2 Sheets-Sheet 2 `ATTORNEYS United States Patent O 3,094,599 SUBMERGED PUMP PROTECTOR Justin E.Wilder, Goshen, Ind., assignor to Penn Controls, Inc., Goshen, Ind., a corporation Filed Feb. 19, 1960, Ser. No. 9,776 4 Claims. (Cl. k200m-122) This invention relates generally to apparatus for use with `water pumps operated while submerged in wells and ink particular to a safety apparatus forshutting Vdown the pump when abnormal conditions exist within the Well.

In cert-ain Well'installations, the pump for delivering water at the well-head is physically located within the well and operates submerged below the water level in the well. An installation of the type referred to is disclosed in Armstrong et al. No. 2,577,559. The pump .is designed so as not to overheat when so submerged, however, should t-he water table fall to an abnormally low level, for example, operation of the pump unsubmerged for even a relatively short period will cause damage necessitating removal of the pump from the well for repair or replacement. In the submerged-type pump installation the pump is usually `controlled by a conventional pressure switch which responds to variation in pressure within a pressure tank connected between the pump discharge and the water service line. Should the pump fail to `deliver water to the tank because of, for example, abnormally low water table conditions, the pressure switch will continue to operate the pump resulting in the damage previously referred to.

The presentinvention provides a control which shuts downthe pump a timed period `after it is started by the conventional pressure control if, and only if, no water is delivered to the pump discharge line.

An object of the present invention is to provide a protective control for submerged pumps which functions to shut down the pump a predetermined time after it has started, the shut-down function being disabled if water at the required ow-rate is delivered by the pump within the predetermined period.

A further object of the present invention is to provide a thermal motor or warp `element assembly which is characterized by relatively rapid response and relatively large rectilinear movement of its output member for a given temperature variation.

A furthery object of the present invention is-to provide a thermal motor of the type referred to` which is compensated fory changes in ambient temperature.

The full nature of the invention will be understood from the accompanying drawings and the following description and claims:

FIG. 1 is a side view of the control apparatus of the present invention with-a portion of the switch enclosure removed.

FIG. 2 is a top plan view with the upper switch housing removed.

FIG. V3 is a sectional view taken generally along the line 3-3 of FIG. 1.

FIG. 4 is a side view of the thermal operator assembly.

FIG. 5 is a top plan viewof one of the bimetal strips incorporated in the thermaloperator assembly.

FIG. 6 is a top plan view of the electric heater forming a part of the thermal operator assembly.

FIG. 7 is an enlarged end sectional view of a portion of the control.

FIG. 8 is an end view of the lower portion of the control.

FIG. 9 is -a schematic wiring diagram showing the control integrated into a pump control system.

FIG. 10 is a schematic wiring diagram illustrating a -is an extension 43 formed of insulating material.

3,994,599 Patented June 18, 1963 "ice 2 modiiied form of pump control circuit into which the control of the present invention may be integrated.

FIG. ll -shows a further modiiied schematic wiring diagram utilizing the present invention Referring initially to FIGS. l, 3-7, the ow responsive portion of the control will be initially described. The control includes a body or tting 10 which is threaded at its lower end for insertion into a T-iitting (not shown) incorporated in the discharge line of a submerged pump. The central bore or cavity 11 within the body 10 thus communicates with the discharge line of the pump. The upper end of the cavity 11 is enlarged to provide `a shoulder 12 from which ex-tends an annular boss 13. Clamped against the boss is a ilexible diaphragm 14 which extends across the cavity and seals its upper end. A plug 16 -t-hreaded into the member 10 bears against a washer 1'7 having a tongue 17a extending from its margin and into -an aperture 18 in the body 10. Interposed between the diaphragm and the washer 17 is a trunnion bearing washer 19.

yAn elongated element, indicated generally at 21, formed of a lower section 22 and an upper hex-sided section 23, extends through a suitable aperture in the diaphragm. The upper end of the section 22 is threaded-and is received within the threaded bore formed in the upper section 23. The lower end of the section 23 bears against a trunnion bearing 24. The bearing 24 is provided with sidewardly yextending tabs 24a which are coni-ined by trunnion bearing washer 19, plug 16 and notches in two sides of locating washer 17. The elongated element 21 thus extendsthrough the base plate 31 of the switching enclosure 32. The diaphragm serves to seal the enclosure 32 from the body 10, but permits the transmission of mechanical motion of the element 21 into the switching enclosure. As may best be seen in FIGS. 1 and 8, the lower end of the section 22 is curved somewhat and has attached thereto by means of screw 34 a iloW-intercepting plate 36.

Referring. particularly toFIGS. 1-6, the switching components of the ycontrol will now be described. The enclosure 32 is formed by the base plate 31 and integral side members 37 and 38. A cover member (not shown) may `be snapped over the Vertical, spaced side members 37 and 38. A generally U-shaped lining of flexible insulating material 39 may be positioned within-the enclosure. As may best be seen in FIG. 3, the upper end of the section 23 of the elongated element 21 receives a screw 41 which clamps to thesection 23 a switch operating arm 42.

Riveted to the sidewardly extending end of the arm 42 The free end of the extension 43 overlies thefree end of a resilient switch blade 44. A tab 46, integral with the arm 42 and extending through the extension 43, serves to retain 'a compression spring 47 whose lower end bears against the base plate 31.

The resilient blade 44 carries a switch contact 48 which cooperates with a further switch contact 49 carried Kby a switch arm 51. The blade 44 and arm 51 are supported in spaced relation by stacked insulating members 52 clamped together by means of -screws 53. The ends 51a and 44a ofthe arm and blade provide suitable terminals for the connection of appropriate wiring. The blade 44 is provided with an inherent bias which urges the contacts 48 and l49 into closed position. As will be apparent from FIG. 1, the spring 47 urges the arm 42 upwardly and consequently urges the plate 36 into its extreme righthand position as shown in FIG. 1. When water flowing through the pump discharge line itnpinges .on the plate 36, the plate will be moved leftwardly as viewed in FIG. 1, causing the extension 43 to move downwardly to displace the blade 44 and open the contacts 48 and 49.

Extending vertically 4from the base plate 31 are stationary posts 56 and 57 which are enlarged at their lower end to provide retaining shoulders 56a and 57a. Extending upwardly from the base plate 31 is a post 58 whose shank is threaded, the post being threaded through a suitable aperture in the base plate 31 with its screwdriver slotted head (not shown) kaccessible from the exterior of the switching enclosure. A lock nut 59 serves to clamp the post S8 in adjusted position. The unthreaded, reduced diameter, upper end 58a of the post extends freely through an aperture 61 in the rst lbimetal strip 62, shown in detail in FIG. 5. The bimetal -strip is provided with tongues 61a which extend out of the plane of the strip and is provided also with apertures 60 and 63 which freely accommodate the posts 57 and 56, respectively.

Overlying the strip 62 and spaced therefrom is an identical second bimetal strip 64 which is provided with apertures freely accommodating the posts 56 and 57 and the reduced end 58a of the post 58. The tabs 61a and the `counterpart tabs formed on the strip 64 serve to hold the two strips in spaced relation. rIhe upper tip of the post 58 extends freely into the `central bore of a ilanged member 66. 'Ihe upper end of the member 66 bears against the lower face of a third bimetal strip 67 which is identical to the strip 62 except that it need not be provided with a central aperture since the member 66 merely bears against, but does not extend through, the strip 67. Overlying the strip 67 is a wi-re wound electric heater assembly indicated generally at 68 and shown in detail in FIG. 6. The heater assembly includes a ibreboard strip 69 having a wire wound electric heater 71 disposed thereon. Terminals 72 permit electrical connection to opposite ends of the heater and the terminal 73 permits electrical connection to the midpoint of the heater. This arrangement is thus such that the heater may be used on either a l() volt or a 220 volt power source. Enclosing the heater and the strip 69 is an envelope 74 of flexible, heat resistant material, the assembly being clamped together by means of brass sleeves or eyelets 76 and, as may best be seen in FIG. 4, the eyelets have substantial mass so as to provide thermal conduction to the strip 67 and the overlying fourth bimetal strip 78. The strip 78 is identical to the strip 62 except that a thrust pin 79 is rigidly secured thereto and extends vertically from the upper face of the strip.

As may be seen in FIG. 2, the thermal operator or warp element assembly is disposed at an angle with relation to the longitudinal axis of the switch enclosure 32, however, this assembly is shown in a full side view in FIG. 4. In FIG. 4, arrows are shown indicating the directions in which the bimetal strips move when their temperature is raised. Strip 62 and the strip 64 have their high expansion sides facing each other, while the strips 67 and 78 have their low expansion sides facing each other with the heater assembly 68 interposed therebetween. The posts 56 and 57, extending through the ends of the strips, serve to confine the free ends of the strips against sideward movement. Thus, upon energization of the electric heater "71, the strip 78 will bow upwardly so that its upper face is convex and the strip 67 will bow so that its lower face is convex. With the center of strip 67 held xed in position by the member 66 the upward movement of the ends of the strip 67 will raise the ends of the strip 78. The upward movement of the central portion of the strip 78, as a result of its assuming a bowed conguration, serves to move the thrust pin 79 upwardly and this motion of the pin 79 will have a magnitude which is the sum of motion components provided by warping of the strip 67 and of the strip 78. When the heater 71 is de-energized, the resulting lowering of the temperature of the strips 76 and 78 causes the thrust pin 79 to retreat downward-ly.

Ambient temperature compensation is provided for the thermal operator by the bimetal strips 62 and 64. These strips are arranged so that upon ambient temperature change the motion provided by strips 67 and 78 is cancelled by motion in the reverse direction by strips 62 and 64. The position of the thrust pin 79 is thus retained relatively stable for variations in ambient tempera-ture. Ihe time delay occuring between energization of the heater 71 and the desired motion of the pin 79 is thus relatively independent of the ambient temperature conditions at the mounting location of the control.

Extending between the side members 37 and 38 in overlying relation to the thermal `operator assembly is a normally closed switch 8-1. The switch is disposed within an enclosure of insulating material and, since it forms no part of the present invention, its specific construction is not disclosed in detail herein. The thrust pin 79 eX tends into the switch housing and functions to operate the switch to open position when moved upwardly by the thermal operator.

Referring to FIG. 9, a typical circuit incorporating the control of the present invention will be described. The power input terminals `82 and 83 are connected to one side of a double pole throw switch indicated generally at 84. The switch 84 is a conventional pressure switch operated by a pressure responsive element, indicated schematically at 86 which responds to the pressure in the pump system pressure tank. The function of the pressure switch is to close the circuit to the pump motor 87 whenever the pressure in the pressure tank falls below a predetermined point and to open the circuit to the pump motor whenever the pressure in the pressure tank reaches the desired value. Also connected in the circuit to the pump motor 87 is the double pole, double throw, normally closed switch 81 which is a component of the control of the present invention. The thermal operator 68 is indicated schematically in FIG. 9. Between the switches 81 and 84 there is interposed the electric heater 71 and in series circuit therewith the switch 48-49. When the pressure switch `84 is closed the pump will be operated and the heater 71 will be energized. Within a timed period after energization of heater 71, the thermal operator 68 will open the switch 81 to shut down the pump. This action of the thermal operator will occur unless, within the timed period, the desired water flow is achieved at the pump discharge line. Under normal operating conditions, the water iiow will move the plate 36 to open contacts 48-49 prior to opening of the switch 81 by the thermal operator. Should the ow through lthe pump discharge line `fail to occur within the timed period, the heater 71 will remain energized and the thermal operator lwill hold the switch 81 open, maintaining the pump shut down.

Referring to FIG. 10, a somewhat modied circuit is schematically disclosed. This circuit is similar to that of FIG. 9 and the components are given the same reference numerals. It is distinguishable from the circuit of FIG. 9 in that the heater 71 is connected to the power input lines between the switch 81 and the pump motor 87. In this arrangement when the thermal operator 68 opens the switch 81, the heater 71 is deenergized and upon the subsequent cooling of the bimetal strips, the switch 81 is reclosed. The pump motor is thus restarted or recycled after a shutdown by the thermal operator.

The circuit of FIG. ll is the same as that shown in FIG. 10, however, the thermal operator is arranged so that when heated, it assumes a position opening switch 81 but cannot reclose the switch 8-1 upon cooling. A push button 91 schematically illustrates a means for returning the thermal operator to its cold position to reclose the switch 8-1. The lockout feature of the circuit of FIG. 9 is electrically maintained, while that of FIG. 11 is mechanically maintained with the push button 91, or a similar reset means being available for manually reclosing of the switch 81.

While the invention has been disclosed and described in some detail in lthe drawings and foregoing description, they are to be considered as illustrative and not restrictive in character, as other modifications may readily suggest themselves to persons `skilled in this -art and within the broad scope of the invention, reference being had to the appended claims.

The invention claimed is:

1. A thermally responsive operator comprising iirst and second bimetal strips disposed in stacked relation with each other a thrust member extending centrally from the outer face of the said second element, a third and fourth bimetal strip disposed in stacked relation with each other, said thrust member centrally engaging the outer face of said third strip, an electric heater interposed between said third .and fourth strips, a thrust pin extending centrally .from the -outer face of said fourth strip, said first and second bimetal strips having their high expansion sides facing each other, said third and yfour-th bimetal strips having their low expansion sides facing each other, and means confining the free ends of said strips against sideward movement, whereby upon energization of said heater said third and fourth bimetal strips assume a bowed configuration and thereby move said thrust pin rectilinearly, said fir-st and second bimetal strips serving to maintain the Work output available at said thrust pin substantially independent of ambient temperature change.

2. A thermally responsive operator comprising iirst and second `bimetal strips disposed in stacked relation with each other, a thrust member extending centrally from lthe outer face of the said second element, a third and fourth bimetal strip disposed in stacked relation with each other, said thrust member centrally engaging the outer face of said third strip, an electric heater disposed in heat exchange relation with said third and fourth strips, a thrust pin extending centrally from the other face of said fourth strip, said rst and second bimetal strips having their high expansion sides facing each other, said third and fourth bimetal strips having their low expansion sides facing each other, and means confining the free ends of said strips against sideward movement, whereby upon energization of said heater said third and fourth bimetal strips assume a bowed configuration and thereby move said thrust pin rectilinearly, said rst and second bimetal strips serving to maintain the work output available at said thrust pin substantially independent of ambient temperature change.

3. A thermally responsive operator comprising iirst and second bimetal strips disposed in stacked relation with each other, a thrust member extending centrally from the outer face of the said second element, a third and fourth bimetal strip disposed in stacked relation with each other, said .thrust member centrally engaging the outer face of said third strip, an electric heater disposed in heat exchange relation with said third and fourth strips, said first and second bimetal strips having their high expansion sides facing each other, said third and fourth bimetal strips having their low expansion sides facing each other, and means confining the free ends of said strips against sideward movement, whereby upon energization of said heater said third and fourth bimetal strips assume a bowed configuration, said rst and second bimetal strips serving to maintain the work output available at the central portion of said fourth strip substantially independent of ambient temperature change.

4. A thermally responsive operator comprising two bimetal strips disposed in stacked relation with each other, an electric heater interposed between said strips, a thrust pin extending centrally from `the outer face of one of said strips, said bimetal strips having their low expansion sides facing each other, means conining the free ends of said strips against sideward movement whereby upon energization of said heater said bimetal strips assume a bowed configuration with their convex faces outward and thereby move said lthrust pin rectilinearly, and means for varying the position of the central por-tion of the other of said strips in response to ambient temperature changes.

References Cited in the tile of this patent UNITED STATES PATENTS 406,152 Sturtevant July 2, 1889 1,784,205 Seeger e Dec. 9, 1930 1,814,812 Klees et al July 14, 1931 1,834,375 Bletz e Dec. 1, 1931 1,894,842 Appelberg Jan. 17, 1933 1,980,799 Hardesty Nov. 13, 1934 2,207,422 Vaughan et al July 9, 1940 2,698,368 Lehr et al Dec. 28, 4 2,830,157 Patti Apr. 8, 1958 

1. A THERMALLY RESPONSIVE OPERATOR COMPRISING FIRST AND SECOND BIMETAL STRIPS DISPOSED IN STACKED RELATION WITH EACH OTHER A THRUST MEMBER EXTENDING CENTRALLY FROM THE OUTER FACE OF THE SAID SECOND ELEMENT, A THIRD AND FOURTH BIMETAL STRIP DISPOSED IN STACKED RELATION WITH EACH OTHER, SAID THRUST MEMBER CENTRALLY ENGAGING THE OUTER FACE OF SAID THIRD STRIP, AN ELECTRIC HEATER INTERPOSED BETWEEN SAID THIRD AND FOURTH STRIPS, A THRUST PIN EXTENDING CENTRALLY FROM THE OUTER FACE OF SAID FOURTH STRIP, SAID FIRST AND SECOND BIMETAL STRIPS HAVING THEIR HIGH EXPANSION SIDES FACING EACH OTHER, SAID THIRD AND FOURTH BIMETAL STRIPS HAVING THEIR LOW EXPANSION SIDES FACING EACH OTHER, AND MEANS CONFINING THE FREE ENDS OF SAID STRIPS AGAINST SIDEWARD MOVEMENT, WHEREBY UPON ENERGIZATION OF SAID HEATER SAID THIRD AND FOURTH BIMETAL STRIPS ASSUME A BOWED CONFIGURATION AND THEREBY MOVE SAID THRUST PIN RECTILINEARLY, SAID FIRST AND SECOND BIMETAL STRIPS SERVING TO MAINTAIN THE WORK OUTPUT AVAILABLE AT SAID THRUST PIN SUBSTANTIALLY INDEPENDENT OF AMBIENT TEMPERATURE CHANGE. 